March 1, 2011: Once more, the competition between the American KC-767 and European KC-330, to replace the aging U.S. Air Force KC-135 aerial tankers, was won by Boeing's KC-767 (as the KC-46A). Three years ago, the air force selected the KC-330, but lawyers and politics upset that award, and the selection process had to be repeated. Nine years ago, KC-767 won the competition, but corruption tainted that award, and the order was cancelled. The latest award may be challenged in court again. After all, it's a big sale. The initial order is for 18 aircraft (at about $150 million each), to be delivered in the next six years. That initial order also comes with about a billion dollars for development work. The air force might order over a hundred KC-46As, but the exact number depends on what kind of future aircraft the air force will be using. If there are a lot of unmanned aircraft (UAVs), fewer tankers will be needed (because UAVs are smaller, and need less fuel). There is, however, a lot of resistance in the air force and Congress to any further squabbling over who should build the replacement for the KC-135.

The KC-330 carries 20 percent more fuel than the KC-767, plus more cargo pallets (26 versus 19) and passengers. But this apparently worked against the KC-330, as the KC-767 is closer in size to the KC-135, and thus will not require as many new maintenance facilities. The KC-767 is also considered easier and cheaper to maintain. The KC-45A was to have cost about $175 million each (17 percent more than the KC-46A).

The KC-767 is based on the Boeing 767-200 airliner, which sells for about $120 million. The 767 has been in service since 1982, and over 800 have been manufactured so far. Boeing developed the KC-767, at a cost of nearly a billion dollars, on its own. Boeing also developed the original KC-135 tanker in the 1950s, and has since built over 2,000 of these.

The two engine KC-330 (KC-45A) is based on the AirBus 330 (which costs about $160 each). About 750 330s have been produced since the aircraft entered service in 1994. Both candidates are replacing the four engine KC-135. This older aircraft carries 90 tons of fuel and can transfer up to 68 tons. Typically, aerial tankers have to service B-52s, which carry over 140 tons of jet fuel, and fighters like the F-15 (over five tons). The KC-135 has long made itself useful carrying cargo and passengers, as well as fuel, and both the KC-767 and KC-30 have more capacity for this.

The KC-767 was developed partly because it is about the same size as the KC-135 (wingspan is 50.3 meters/156 feet, 6.8 percent larger than the KC-135). Thus the 767 could use the same basing and repair facilities as the 135. In the meantime, Japan and Italy have ordered eight KC-767s. So far, 28 KC-330s have been sold to Australia, Saudi Arabia, the United Arab Emirates and Britain.